Bridge plate assembly



Aug. 31, 1 J. E. GUTRIDGE 3,203,364

BRIDGE PLATE ASSEMBLY Filed Dec. 11, 1963 3 Sheets-Sheet 1 INVENTOR.

JA CK E GUTR/DGE WM KMZ Aug. 31, 1965 J. E. GUTRIDGE BRIDGE PLATEASSEMBLY 3 Sheets-Sheet 2 Filed Dec. 11, 1963 INVENTOR.

Aug. 31, 1965 Filed Dec. 11, 1963 J. E- GUTRIDGE BRIDGE PLATE ASSEMBLY 3Sheets-Sheet 3 INVENTOR. JA CK E GUTR/DGE United States Patent 3,293,364BRIDGE PLATE ASSEMBLY Jack E. Gutridge, Dyer, Ind, assignor to PullmanIncorporated, Chicago, 'Ill., a corporation of Delaware Filed Dec. 11,1963, Ser. No. 329,663 6 Claims. (Q1. 105458) This invention relates toa railroad car of the low side open deck variety particularly adaptedfor piggyback hauling service and more specifically relates to a new andimproved lightweight bridge construction including means to maintain thebridge in a cushioned upright position when not in use.

Railroad cars particularly suited for piggyback type hauling have foundwidespread acceptance in the railroad industry. Each of the cars isequipped with bridge plates at diagonally opposite corners so that whena plurality of cars are coupled together the bridge plates may belowered to span the gap between the cars to permit the loading ofwheeled vehicles by merely driving them to the appropriate car. In manyinstances the vehicle or lading will comprise one or more highwaytrailers, which are usually loaded two to a car. Since most of thehighway trailers are of great length, it is virtually impossible to foldthe bridge plate to a horizontal position overlying a portion of thedeck when not in use, since the ends of the trailers are closelyadjacent the front and rear end of the car. Assuming that a satisfactoryclearance was available, it is exceedingly laborious, difiicult andcumbersome to rotate the bridge through a 180 arc to put the same intoor out of use.

Accordingly, it has been customary to lock the bridges in a generallyvertical position when not in use. The many forms of shock loading wellknown in the rail industry require that the bridges be securely mountedand locked in such a fashion that the hinge and locking structure willbe protected. Shock mechanisms of varying complexities have been tried,however have been unsatisfactory for one reason or another such asrequiring great expense in construction, occupying valuable load spaceand being unable to withstand repeated shock loading to mention a few.

Further problems have been encountered since the perfection of shockdissipating cushioning means for railway cars. Many of the piggybackfiat cars now being manu factured include such cushioning means, andmany existing flat cars are being modified to incorporate shockdissipating and cushioning means. Cushioning means for fiat cars quiteoften include a sliding sill type cushioning arrangement which basicallyincludes a longitudinally continuous sill structure slidably received ina box-like center sill in the underframe of the car. Couplers aremounted at the opposite ends of the sill while a suitable hydraulic orother type of cushion operatively interconnects the sliding sill withthe underframe of the car. When a railway car is so equipped andreceives an operational shock in buff or draft, the cushioningarrangement absorbs substantially all of the shock which results in arelative longitudinal movement between the sliding sill and theunderframe of the railway car.

In order to accommodate this movement of the sliding sill, it has beennecessary to space the couplers at the ends of the sliding sill asubstantial distance beyond the ends of the flat cars. With theattendant increase between coupled cars, due to the increased spacing oftheir respective couplers, it has been necessary to provide each I ofthe cars so equipped with bridge plates of a long length,

i the present invention. The bridge plate about to be deice scribed indetail, employs a central plate member of light-weight constructiontrimmed at opposite ends by a pair of identical ramps. One of the rampsis equipped with the central bore which receives a hinge pin carried bythe car; an elastic locking means is also carried by the hinge pinhaving suitable means to co-operate with a sliding lock member on thebridge plate. Although the bridge plate may be of unusual lengthscompared to existing prototypes, the light-weight construction allowsthe elastomeric locking means to maintain it in a substantially uprightposition throughout periods of operational shock. Moreover, the elasticlocking means serves to dissipate energy generated by operational shockbeing transferred to the bridge plate. Accordingly, it is a principalobject of this invention to provide a new and improved form of bridgeplate particularly adapted to obviate the problems enumerated above.

It is a further object of this invention to provide a new and improvedlight-weight bridge plate construction for use on a piggyback railwaycar having a new and improved form of locking means to resilientlymaintain the bridge in an upright position when not in use.

It is a further object of this invention to provide a novel lockingmechanism of uncomplicated and relatively inexpensive construction whichwill limit and control the angular movement of the bridge in an uprightposition.

It is a still further object of this invention to provide a new andimproved locking means for a bridge plate assembly which may be easilyoperated from the locked to unlocked position.

Further and fuller objects will become readily apparent when referenceis made to the accompanying drawings wherein:

FIG. 1 is a fragmentary perspective view of the end portions of two carscoupled together with their respec tive bridge plates in the uprightposition;

FIG. 2 is a view similar to FIG. 1 with the bridges in the loweredposition to permit passage of vehicles from one car to the other;

FIG. 3 is a cross sectional view taken along the lines 3-3 of FIG. 1;

FIG. 4 is an enlarged fragmentary side elevational view of the lockingmechanism of the instant invention; and

FIG. 5 is a cross sectional view taken along the lines 55 of FIG. 4 withthe bridge plate broken in the central section.

FIG. 1 illustrates the ends of two cars indicated generally at 10 and 11held in coupled engagement by a coupling mechanism indicated generallyat 12. One end of a longitudinally continuous sliding sill is shown,being received in a box-like center sill 51 which is rigidly secured asa part of the underframe structure of the car. The car 10 includes a bedor deck portion having low side portions 53 and 54 to insure that thelading remains on the car as it is pulled over the deck 52.

In FIG. 1 the bridge plates 13 and 14 are illustrated in the locked orupright position, however as seen in FIG. 2, each of the bridge plates13 and 14 has been unlocked and rotated to the down position to providea pair of generally flat deck portions 15 and 15' respectively, tosupport vehicles or other forms of wheeled lading passing from one carto the other. Bridge plate 14 is identical in construction to the oneillustrated at 13, as well as the bridge Plate at the other ends of thecars (not shown), so in the interest of brevity, the description will belimited to the bridge plate 13.

With the bridge plate 13 in the down position, the coupling arrangementbetween the cars 10 and 11 is exposed to show the sliding sills 50 and55 having outwardly flared coupler housings 56 and 57 respectively. Eachof the coupler housing 56 and 57 carries a conventhis relative movement.

. by means of rivets, bolts, welding or the like.

is of identical construction permitting a single extrusion tionalcoupler 58 and 59 respectively which is pivotably mounted in aconventional manner within the flared coupler housing slidably receivingeach of the sills.

It is to be understood that a hydraulic or other type cushion, such asthat shown in the US. Patent No.

3,003,436, operatively interconnects each of the sills 5i) and 55 to theunderframe of the respective cars and 11.

Operational shock in bull or draft applied to the couplers of therailway cars 10 and 11 are absorbed by the cushioning means, whichresults in relative movement between the sill and the cart. Suchrelative movement can be on the order of 20 to 40 inches in eitherdirection making it necessary to space the couplers a substantialdistance from the end sill of the car in order to accommodate Thisincreased spacing requires bridge plates used in conjunction therewithto be of sufficient length to span the increased distance between theend sills.

The flat deck portion 15 of the bridge plate 13 is pro- 'Vidd at eachend with a ramp 16 and 17 to allow a smooth transition of the vehiclefrom the deck of one car across the bridge plate and onto the deck ofthe other car. The ramp 17 also forms a housing for co-operation with ahinge assembly indicated at 18 to mount the bridge plate on the car forpivoting or angular movement. locking pin 19 is 'slidably carried on oneside of the bridge plate 13-for slidable reception in a lockingreceptacle 20 carried by the hinge structure 18. The details of theconstruction will be described more specifically in connection withFIGS. 4 and 5.

As illustrated in FIG. 3, the flat deck portion 15 has a series of webs21 depending therefrom with each web 21 terminating in a transverselyextending flange portion 22 to resist the tensile forces when the bridgeplate is loaded. This section of the bridge may be formed in anysuitable manner as by joining a series of I beams having -a wide upperflange, or alternatively through an extrusion -or like process.

' acceleration are minimized by reducing the overall mass to a minimum.The torque applied to the locking mechanism under impact is equal to themass of the body times the radius to the center of the mass squared,times the angular acceleration. Therefore, evaluating the total ap- Iplied torque, any reduction in mass of the rotating body results in aproportionate reduction in the applied torque allowing considerablereduction in the required strength of the hinge and locking structure.

Adjacent one edge portion of the bridge structure, a pin guide isprovided for slidably supporting the locking pin 19. The pin guide isbifurcated to form a pair of leg members 24 and 25 one one side, and hasa generally cylindrical slot 26 to guidingly receive the pin 19 on theopposite side. The pin guide 23 may be fastened to the bridge structureby means of rivets, welding or the equivalent, and may be positioned atany point along the edge so long as the pin is of sufiicient length toengage the pin receiving receptacle 20.

The enlarged views of FIGS. 4 and 5 illustrate the cooperativeengagement of the locking pin 19 and the associated receptacle 20,together with an elastomeric means which resiliently holds the bridge inan upright position. The ramp portion 17 is attached to one end of thebridge plate, and is of uniform extruded construction having a pair ofspaced leaf member-s 28 and 29 disposed on opposite sides of the bridgeplate 13 and fastened thereto Ramp 16 to be used which will trim bothends of the assembly and protect the tires of vehicles from damage whichcould be caused by exposed sharp edges.

The leaf portions 28 and 29 of the ramp 17 extend across the end of abridge, with the portion 28 being integral with a gentle incline 30which merges in an arcuate manner (as at 31) with the lower leaf 29. Thecentral Section of the arcuate portion 31 of the ramp 17 is providedwith a cylindrical bore 32 to receive the hinge pin 33. A pair ofmounting brackets 34 and 34 are fastened to the end sill of the car withthe hinge pin 33 being welded to each bracket in the manner illustratedon mounting bracket 34 at 35.

The elastic support means is shown generally at as including an outerbushing 41 coaxially disposed about an inner bushing 42. The innerbushing 42 is received on the hinge pin 33 with a press fit so as to benon-rotatable with respect thereto. Obviously, the hinge pin 33 may beformed of non-circular configurations to prevent the occurrence ofrelative rotation between a complementary configured bore in the innerbushing 42. For example, the hinge pin 33 may be provided with arectangular cross section, keyed connection or the like for joining tothe inner bushing 42. An elastomeric sleeve 43 is shot between thecoaxial bushings 41 and 42, and due to the substantial compressionrigidly grips the outer circumferential surface of the bushing 42 andthe inner circumferential surface of the bushing 41 so as to preventrelative rotation between each of the bushings and the associatedsurface of the elastomer 43. In one specific embodiment, the elastomericmaterial comprised rubber of the order of 65 Durometer hardness, havinga radia hickness of about five-eighths of an inch.

A pair of downwardly projecting lug members 60 and 61 are integral withthe outer bushing 41 and have inwardly facing stop surfaces 62 and 63for co-operation with a fixed stop block 65 attached to the deck 52. Inthis connection, it is to be appreciated that all the structureassociated with the bridge plate is disposed above the deck so as to becompletely clear of the underframe, sliding sill and the like so as tonot interfere therewith. In addition, the bridge plate and lockingassembly of the present invention is installed on new or existing carswith a minimum amount of effort.

The pin receiving pocket 20 is formed integral with or afiixed to theouter bushing 41 by means of welding or the like. As illustrated inFIGS. 4 and 5, the pocket 26 receives the free end portion of the pin 19which has a tapered arcuate end portion to assist in guiding the pininto the socket. When the bridge plate is in the position shown inphantom in FIG. 4, the pin 19 is received within the pocket 20 to holdthe bridge plate section in a substantially upright position. Unlockingof the bridge plate is easily accomplished with the novel locking meansof the present invention. The resilient mounting of the pin receivingpocket permits the bridge plate to be rocked back and forth to free thelocking pin to allow withdrawal thereof, should it become frozen orstuck in the pin receiving pocket.

During switching operations, coupling and uncoupling of the cars, aswell as in transit, substantial impact loads will cause the bridge plateto attempt to pivot. In the past, a variety of complicated mechanismshave been provided in an effort to prevent and/or control the pivotingmovement thereof, however have not been successful, or alternatively arefar too expensive for widespread commercial application. In addition,prior art prototypes generally are fastened beneath the deck structureand are not suited for applications wherein the whole end of the carmoves in response to shock loading forces.

In the present invention, impact loading forces which attempt to rotatethe bridge plate are transmitted through the pin guide to the lock pin19, and then to the outer bushing 41. Under this arrangement, outerbushing 41 attempts to rotate with respect to the non-rotatable innerbushing 42, causing torsional forces to arise in the elastomer section43. Since the elastomer section 43 is resilient, a slight rotation ofouter bushing 41 occurs with the rubber being placed in shear,permitting the bridge structure to move through a slight angle eitherclockwise or counterclockwise from the static point shown. In the eventthe dynamic loading forces are sufficient to rotate the outer bushing 41to a degree that the elastomer approaches a maximum shear condition,further rotation is prevented by the appropriate lug 60 or 61 cominginto contact with the stop block 65 to prevent further rotationalmovement. This serves to protect the elastomeric bushing from beingstressed beyond its elastic limit. It is to be appreciated however thata greater portion of the dynamic forces developed are dissipated in theelastomeric bushing 43 before the lugs 60 and 61 engage the stop block65, so the final impact will be of a low order of magnitude. The totalangular swing of the bridge plate is easily governed from about 40 or 50on either side of a neutral position to lesser angles by adjusting thelongitudinal dimension of the stop block 65.

In one specific embodiment of the invention, the angularity of thebridge under static or locked conditions was of the order of aboutfifteen degrees with respect to a purely vertical plane. Under suchcircumstances, the angular movement was controlled between a purelyvertical position and about 25 on the other side of the static position,limiting the total pivoting movement to a total of about 40. Obviously,this prevents the bridge from striking lading carried on the car whilethe elastomeric locking means is resiliently absorbing the energy ofimpact forces generated by the mass of the bridge plate. The elastomericlocking means controls the angular movement of the bridge plateabsorbing and damping the applied shock forces in such a manner thatlittle if any force is left at the point where the lugs 60 and 61 engagethe stop block 65 to provide a positive limit to the angular travel ofthe bridge plate.

Since the static position is slightly angulated with respect to a purelyvertical direction, the weight of the bridge constitutes one force whichresists counterclockwise movement towards the lading on the car. Underthe above conditions, the maximum angular movement from the staticposition counterclockwise will always be somewhat less in magnitude thanthe angular movement in a clockwise direction because the forces ofgravity will subtract from the total dynamic forces on the bridgesection. It is obvious that greater clockwise movement under impact ispermissible since no obstructions exist between the cars other than theend of an adjacent car.

While a specific type of lightweight bridge plate has been illustratedand described, it is not intended to limit the invention to thisspecific type since it is readily apparent that the novel locking meansmay be applied to other forms of bridge plates. It will becomeimmediately obvious to those skilled in the art, that othermodifications and variations of the invention may be made withoutdeparting from the spirit and scope thereof and therefore, only suchlimitations should be imposed as are indicated in the appended claims.

I claim:

1. In a railway car particularly adapted for piggyback ladingoperations, said car having coupling means projecting from one endthereof to co-operate with the next adjacent car, the provision ofpivoting bridge plate means carried at diagonally disposed ends of saidcar for projectmg over to the next adjacent car, said bridge plate meansof sufficient transverse width to permit wheeled lading to be driventhereover when spanning the distance between adjacent cars, said bridgeplate means having hinge means at one end thereof for pivotably mountingsaid bridge plate means on said car for angular movement about agenerally horizontal axis, a. locking pin member carried by one of saidbridge plate means and said car, a pin receivmg pocket member on theother of said bridge plate means and said car, and elastomeric meansresiliently mounting one of said members to torsionally control anddampen the angular travel of said bridge plate means under shock loadingwhen said bridge plate is locked in a transit position.

2. A railway car of the generally flat deck variety, said car beingadapted to receive Wheeled vehicles for transportation thereof, a bridgeplate positioned at one end of said ear to permit said wheeled vehiclesto be driven thereover when lowered, a hinge structure supporting saidbridge plate for pivoting movement between a horizontal position and agenerally upright position, locking means cooperating with said bridgeplate and said car resiliently maintaining said bridge plate in agenerally upright posi tion between defined angular limits duringperiods of nonuse, said locking means including a pin member and pocketmember interposed between said car and said bridge plate and operativelyconnected thereto for lockmg said bridge plate in an upright position,resilient means mounting one of said members, said resilient means beingstressed in torsion to allow limited angular movement of said bridgeplate when locked in a generally upright position to protect said hingestructure and said locking means under conditions of shock loading.

3. The railway car of claim 1 wherein a positive limit means isassociated with said elastomeric means to provrde a positive stop aftera predetermined angular travel of said bridge plate means.

4. The railway car of claim 1 wherein said elastomeric means includesspaced generally coaxial inner and outer cylindrical members having anelastomeric substance therebetween.

5. The railway car of claim 2 wherein said resilient means includesinner and outer cylindrical bushing members being held in coaxialrelationship by an elastomeric substance therebetween, said innercylindrical bushing bemg non-rotatably held by a cross shaft forming apart of said hinge structure.

6. The railway car of claim 5 wherein said outer cylindrical bushing isprovided with a pair of angularly spaced stop surfaces and stop means isprovided on said car to positively limit the total shear force on saidelastomeric substance.

References Cited by the Examiner UNITED STATES PATENTS 2,911,925 11/59Adler et a1 -376 3,063,386 11/62 Price 105-376 ARTHUR L. LA POINT,Primary Examiner.

LEO QUACKENBUSH, MILTON BUCHLER,

Examiners.

1. IN A RAILWAY CAR PARTICULARLY ADAPTED FOR PIGGYBACK LADINGOPERATIONS, SAID CAR HAVING COUPLING MEANS PROJECTING FROM ONE ENDTHEREOF TO CO-OPERATE WITH THE NEXT ADJACENT CAR, THE PROVISION OFPIVOTING BRIDGE PLATE MEANS CARRIED AT DIAGONALLY DISPOSED ENDS OF SAIDCAR FOR PROJECING OVER TO THE NEXT ADJACENT CAR, SAID BRIDGE PLATE MEANSOF SUFFICIENT TRANSVERSE WIDTH TO PERMIT WHEELED LADING TO BE DRIVENTHEREOVER WHEN SPANNING THE DISTANCE BETWEEN ADJACENT CARS, SAID BRIDGEPLATE MEANS HAVING HINGE MEANS AT ONE END THEREOF FOR PIVOTABLY MOUNTINGSAID BRIDGE PLATE MEANS ON SAID CAR FOR ANGULAR MOVEMENT ABOUT AGENERALLY HORIZONTAL AXIS, A LOCKING PIN MEMBER CARRIED BY ONE OF SAIDBRIDGE PLATE MEANS AND SAID CAR, A PIN RECEIVING POCKET MEMBER ON THEOTHER OF SAID BRIDGE PLATE MEANS AND SAID CAR, AND ELASTOMERIC MEANSRESILIENTLY MOUNTING ONE OF SAID MEMBERS TO TORSIONALLY CONTROL ANDDAMPEN THE ANGULAR TRAVEL OF SAID BRIDDGE PLATE MEANS UNDER SHOCKLOADING WHEN SAID BRIDGE PLATE IS LOCKED IN A TRANSIT POSITION.